This weekend Blizzard previewed the warlock Gul'dan, one of the playable characters in their online card game Hearthstone: Heroes of Warcraft. Like warlocks in World of Warcraft, Gul'dan wields destructive magic and can summon demonic minions.

One of the most powerful demons he can summon is the Void Terror. The Void Terror, modeled after the Voidwalker in WoW, is able to absorb minions on either side of them. This will kill the other minions, but add their Attack and Health to the Void Terror. This makes the Terror resilient enough to withstand Hellfire, a warlock spell that burns all the friendly and enemy units in play.

Clever players can use this absorption ability to turn their Void Terror into a juggernaut. For example, they can use the Power Overwhelming card to enhance a minion and then make their Void Terror suck up that minion. The minion's improved stats are then added to the Void Terror.

Hearthstone offers nine playable characters, each representative of a different WoW class. Their choice of minions, weapons and spells varies depending on their class. Blizzard previously showed off the Jaina and Thrall, the mage and shaman characters respectively.